Australian doctors have identified a new and potentially life-threatening condition and, in a welcome twist, they also have the cure.

The Queensland Institute of Medical Research (QIMR) has reported the case of a young NSW woman who had been routinely and mysteriously ill, needing hospital care, for more than a decade.

The woman was found to be suffering from a previously unknown, and as yet unnamed, condition in which her immune system's signalling processes were not working as they should.

"I haven't got a name for it other than 'T-cell signalling defect' of which I assume there are quite a few different types," Dr Maher Gandhi, head of QIMR's Immunohaemotology Laboratory, told AAP on Monday.

"There are no recorded cases of this in the literature. Katie is unique ... I think we're at the tip of the iceberg here."

Katie Pulling, now aged 23, was successfully treated with an experimental bone marrow transplant using stem cells donated by her sister.

The transplant is conventionally used to treat people with leukaemia, as it was known to reboot a patient's immune system.

It was her development of full-blown fulminant infectious mononucleosis, after years in which she suffered the worse possible complications from otherwise routine infections, that pointed doctors to her immune system and, ultimately, its signalling problems.

"The transplant was dangerous but the results were amazing," Dr Gandhi said.

"The defect in Katie's immune cells has been fixed and, to our knowledge, this is the first time this disorder has been reported.

"We hope this will help anyone who has presented with the same symptoms and has had no success with treatments."

The QIMR had worked on Ms Pulling's case for more than three years, and the experimental bone marrow transplant was undertaken at the Royal Brisbane and Women's Hospital.

Ms Pulling lives in northeastern NSW and she is now completing a Bachelor of Business.

"I am now back to full time study and loving it," Ms Pulling said in a statement.

"Now I don't get sick. I am really not used to it and keep waiting to get sick."

Her unique case is detailed in a paper published in the journal Clinical Infectious Diseases.

Sounds like ME to me, but hey, if they want to call it something else, great! Better than what we have now. And the treatment they used, stem cells, is already being used by Dr Cheney for CFS. See the Stem Cell Treatment thread;